Drawing mechanism for spinning frames and similar machines



Aug. 14, 1934. R. D. TARR El AL DRAWING MECHANISM FOR SPINNING FRAMESAND SIMILAR MACHINES Filed Feb. 29. 1932 Patented Aug. 14,1934 I I I IUNITED STATES PATENT OFFICE DRAWING MECHANISM ron SPINNING FRAMES ANDSIMILAR MACHINES Roderic D. Tar-r, Biddeford, and Edmund E. Blake, Saco,Maine, assignors to Saco-Lowell Shops, Boston, Mass., acorporation ofMassachusetts Application February 29, 1932, Serial No. 59537 6 Claims.(01. 19-131) This invention relates to drawing mechanisms 21 rests onthe belt immediately above the for spinning frames and similar machines.It bar 12. is more especially concerned with mechanisms The mechanism sofar described may be, and 1 of this type used in what is known as longpreferably is, substantially like that shown and 5 draft spinningframes, the best example of described in the patent above referred to.The

which is shown in United States Letters Patent sliver is led through therolls in succession, the No. 1,804,968, dated, May 12, 1931, preparationdraft being applied to it between Long draft spinning has been known tlimthe rear rolls 8 and 9 and the intermediate rolls ited extent formany years, but the invention 6 and 7, and it is then subjected to amain draft to disclosed in t patent above mentioned h between theintermediate'and the front rolls.

for the first time made long draft spinning in. The lower intermediateknurled roll 6 drives able in a commercially satisfactory form. The thebelt apron 10 and the T011 14 is made of mechanism shown i aid patent ht suflicient mass or weight to keep the belt taut. very extensive useand has been exceptionally In the arrangement heretofore used this belt7 iii successful, I tensioning roll 14 has been guided to swing about Itis the chief object of the present invention the axis of a rod 16, 4,which'has been further to improve mechai'iisms cf t general located inapproximately the relationship to the type show i th patent, abovedesignated with belt and the roll 14 shown in said figure, and the aview to making them even more reliable. guiding d vi e s be n a ra ed tomaintain $.36 The nat of th invention will be readily the axis of thebelt tensioning roll at a constant understood from the followingdescription when distance from the axis of the rod 16 and 0011- read inc nn ti t t accompanying drawstantly parallel also to the axis of thedriving ing, and the no l feature w be particuiafly roll 6. It has beenthe usual custom; also, to pointed out in th appended claims. make thesebelts of leather, calfskin being very I th drawing commonly employed,and whether made of this Figure 1 is a r elevation of a drawing materialor not it has been necessary to cut mechanism similar t t t shown in thepatent them out of sheet material and to cement the above designated, bt modified in accordance ends together so as to make an endless belt.with the present inv ti It occasionally happens that a belt will not beFi 2 i vertical, Sectional View approxi; cut or cemented exactlystraight so. that one mately on the li 2-2, Fig 1, but indicating sideor margin of the belt will be slightly longer the clearer roll i place;than the other, or one margin of the belt may Fig. 3 is a diagrammaticview illustrating stretch more than the other after it has been tainfeatures of the mechanism shown in Figs. use for a timewhen anySubstantial 35 i and 2; and ference in thelengths of the two margins ofFig, 4 i view similar to 3 but showing the belt occurs, it has beenfound that the belt the prior art arrangement, crowds against one flangeof the roll 14 and The drawin mechanism Shown in Figs 1' 2 curls over,thus producing after a time an l ne and 3 comprises a roll stand 2having suitable satisfactory operating condition- While this an hearingsi hi h th c driven 1 4, 6 d does not occur very frequently and thecrooked a, respectively are mounted Upper rolls 5 7 belts can be removedand replaced, nevertheless and 9 cooperate with the respective r0118 4,6 this condition is not satisfactory. To devise an and 8 to form threepairs of rolls, namely, front effective PP for h problem a by rolls 4and 5, middle or intermediate rolls 6 and these FOndItEODS constltutesthe chief ObJect and back rolls 8 and 9. Usually the lower 9f themYentlon I front and rear rolls are fitted or grooved while Aconslderame Ya-nety of anal-lge-ments haYe the lower middle roll 6 isknurled. Usually also been-used for belt-tensmmng Ions m H 113 9 leather0 r d A It drawing mechamsms 1n WhlOh endless be1ts or 1' upper m ar C Ye e aprons are employed, but all of them of winch f 10 Passes betweenthe mteFmedlate rolls we have been able to learn are objectionable e and'7, runs w d v a statwnary bar 12, because of the action abovedescribed. A careand then extefldsj downwardly a rearwardly' fulanalysis ofthe causes responsible for this a u d a 0 1 14 w l h isprovid d result and exhaustive experiments indicate that a with endflanges to limit the lateral movement the difliculty is caused in somecases, as for @f the belt relatively to the r011- A p roll example inthe arrangement above described,

by an'action between the belt tensioning'roll and the belt, similar tothatwhich occurs in a crowned pulley. Inoth'er' cases the underlyingcause appears to beat; slight twisting action exerted on the beltby thetensioning pulley due to the fact that the axis of the pulley gets outof alinement with the axis of the driving roll.

We have found that these difliculties can be avoided by splitting theguide shown in the patent above designated for the belt tensioning rollso as to permit the two arms of the guide to swing independently of eachother, and by so mounting these guiding arms that the axis of the roll14 will be held approximately in a plane passing through the axis of thedriving roll 6 notwithstanding differences which ordinarily are found,and must be reasonably expected, in the lengths of the two margins ofthe belt 10.

Referring to Figs. 1 and 2 it will be seen that the opposite projectingends of gudgeons of the belt tensioning roll 14 are guided by swingingarms 15-15 both mounted on the rod 16 which is supported in parts of thestands 2. Also, that the location of this rod has been changed ascompared to the arrangement shown in Fig. 4, and that it occupies such aposition that the arms 15-15 guide the roll 14 for belt tensioningmovement in a plane passing through the axis of the driving roll 6. Inother words, the arms 1515.permit the tensioning roll to take anyposition required to maintain the tension on both margins of the beltapproximately equal, notwithstanding differences in the lengths of saidmargins, while at the same time so guiding the two gudgeons of said rollas to maintain the axis of the roll approximately in a plane extendingthrough the axis of the driving roll. With this arrangement, therefore,the tensioning roll may assume various angular relationships to thedriving roll, its axis either being parallel to the axis of the latterroll or not, but the axes of the two rolls always lie approximately inthe same plane. This arrangement has been found to operate highlysatisfactorily.

In an ideal arrangement the plane connecting the axes of the roll 14 androd 16 would lie at right angles to the plane connecting the axes of therolls 6 and 14. Considerations of economy, however, and the necessityfor avoiding interference with the removal of the clearer roll 3'7 fromthe machine and its replacement therein, make it preferable to locatethe rod 16 approximately as shown in Fig. 2, so that the planeconnecting the axes of the roll 14 and the rod 16 are not quiteperpendicular to the plane through the axes of the rolls 14 and 6.However, the relationship is so close to the ideal arrangement abovedescribed that the practical effect is the same, and the belt is guidedwithout any appreciable tendency to crowd endwise of the roll 14notwithstanding substantial differences in the lengths of the twomargins of the belt.

The difierences in the belt tensioning movement produced with thepresent arrangement as compared to a typical prior art construction isillustrated in dotted lines in. Figs. 3 and 4, although'the extremerange of movement of the belt is somewhat exaggerated in proportion tothe other elements. In practice a difference in the length ofone-quarter of an inch in the two margins of the belt would representwhat might belt tensioning roll, however, is so supported that itsopposite ends can drop independently of each other into positionsdetermined solely by the operating lengths of the two margins of thebelt. At the same time any twisting of the belt is prevented and theguiding arrangement is such that approximately the entire weight of theroll is efiective to tension the belt.

The arms 15-15 are held properly spaced from each other and in correctlateral positions by means of spring clips 20 which are snapped over andgrip the rod 16 and which bear lightly against the sides of the guidingarms.

The invention thus improves in a very simple and inexpensive way therunning conditions in a drafting mechanism of the type above described,and completely avoids a difliculty which has been annoying heretofore.It also avoids the presence of any surfaces on which the tensioning rollcan climb due to its rotation and thus move out of its proper runningposition. This has been an objectionable feature of some of the priorart constructions.

A further advantage of this construction is that it results in a moreuniform and better cleaning of the belt 10 by the clearer roll orscavenger roll 3'7. A customary arrangement is to provide a singleclearer roll running in contact with all of the belts 10 of a series ofadjacent drafting units, the roll 37 also bearing lightly against thelower rear rolls 8. Such a clearer roll has gudgeons at its oppositeends which are supported in springs and one of these springs is shown inFig. 2 at 38. Consequently, the clearer roll is maintained yieldinglyina fixed position and it is revolved slowly by its contact with therolls 8 and belts 10. In the arrangements heretofore employed, if one of'the belts stretched more than the others it allowed its belt tensioningroll to drop away from the clearer roll 3'7and resulted either in movingthe belt out of contact with the clearer roll, or in reducing thepressure of the belt against the clearer'roll, with a consequenttendency to reduce the cleaning actionof the clearer on the belt. On theother hand, if one side of any belt stretched more than the other, theresulting twisting action which would be produced in this manner, asabove described, would tend to move the longer margin of the belt awayfrom the clearer roll and might either actually produce this result, orso reduce the pressure against the clearer roll that this part of thebelt could not be properly cleaned.

The present arrangement overcomes both of these difliculties due to thefact that it maintains the taut sides of all the belts of adjacent unitsconstantly in substantially the same plane notwithstanding variations inthe lengths of the belts or differences in the lengths of the twomargins of an individual belt. Each drafting unit, therefore,' is keptconstantly in a better and more uniform condition than has been possible with prior arrangements.

While we have herein shown and described a preferred embodiment of ourinvention, it will be evident that the'invention may be embodied inother forms without departing from the spirit or scope thereof.

Having thus described our invention, what we desire to claim as new is:I

1. In a drawing mechanism of the type in which an endless beltcooperates with additional .devices to grip the roving or sliver duringthedrawing operation, the combination of a driving also obtainingsubstantially all of the belt tensioning eflect oi the latter roll.

2. In a drawing mechanism of the type in which an endless beltcooperates with additional devices to grip the roving or sliver duringthe drawing operation, the combination of adriving roll for said belt, abelt tensioning roll supported by said belt, two pivoted arms forengaging and guiding opposite ends of said belt tensioning roll, andmeans for supporting said arms for swinging movement independently ofeach other about a fixed axis.

3. In a drawing mechanism of the type in which an endless beltcooperates with additional devices to grip the roving or sliver duringthe drawing operation, the combination of a driving roll for said belt,a belt tensioning roll supported by said belt two pivotedanns forengaging and guiding opposite ends of said belt tensioning roll, andmeans i'or supporting said arms for swinging movement independently ofeach other about anaxis positioned to cause said arms to maintain theaxis oi said belt tensioning roll approximately in a plane extendingthrough both said axis and the axis of said driving roll notwithstandingnormal differences in the lengths of opposite margins of said belt.

4. In a drawing mechanism 01' the type in which an endless beltcooperates with additional devices to grip the roving or sliver duringthe drawing operation, the combination of a driving roll for said belt,a roll supported by said belt for tensioning the belt. swinging guidesfor the opposite ends of said belt tensioning roll arranged to allow thetwo ends of the latter tional devices to grip the roving or sliverduring the drawing operation, the combination of a driving roll for saidbelt, a roll supported by said belt for tensioning the belt, andswinging guides tor the opposite ends of said tensioning roll arrangedto maintain the axis oi the latter roll approximately in a planeextendingthrough the axes of both of said rolls while enabling theopposite ends of the belt tensioning roll to rise and fall independentlyof each other due to its own weight to cause said roll to equalize thetension on both margins of the belt notwithstanding diflferences in thelengths of said margins, and means supporting said guides for in:dependent swinging movement.

6. In a drawing mechanism of the type in which an endless beltcooperates with additional devices to grip the roving or silver during.

the drawing operation, the combination of a driving roll for said belt,a belt tensioning roll supported by said belt, two pivoted arms forengaging and guiding opposite ends of said belt tensioning roll, andmeans tor supporting said arms for swinging movement independently ofeach other about an axis located behind and above the axis of said belttensioning roll.

nonmuc D. TARR. EDMUND a. slim.

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